Ventilated Skin Mountable Device
A medical device is provided comprising a transcutaneous device unit and a process unit. The transcutaneous device unit is adapted to be mounted to a skin surface of a subject and comprises a first housing, a transcutaneous device, and may comprise a flexible patch portion with an upper surface and a lower mounting surface adapted for application to the skin of a subject. The process unit comprises a second housing with a lower surface and a process assembly. The first and second housings are adapted to be secured to each other in such a way that the lower surface of the second housing is allowed to move freely relative to at least a portion of the underlying skin surface or patch. In this way a relatively flexible patch portion can adapt to the skin surface to which it is mounted both statically and dynamically without being restricted in its movements by the normally much stiffer process unit.
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The present invention generally relates to a device which is adapted for application to a skin surface of a subject and comprises a transcutaneous device unit and an attachable process unit. In a specific aspect a transcutaneous drug delivery device is provided in combination with a drug delivery unit. In a further aspect a transcutaneous sensor device is provided in combination with a unit processing or transmitting data acquired from the sensor.
BACKGROUND OF THE INVENTIONIn the disclosure of the present invention reference is mostly made to the treatment of diabetes by injection or infusion of insulin, however, this is only an exemplary use of the present invention.
Portable drug delivery devices for delivering a drug to a patient are well known and generally comprise a reservoir adapted to contain a liquid drug and having an outlet in fluid communication with a hollow infusion needle, as well as expelling means for expelling a drug out of the reservoir and through the skin of the subject via the hollow needle. Such devices are often termed infusion pumps.
Basically, infusion pumps can be divided into two classes. The first class comprises infusion pumps which are relatively expensive pumps intended for 3-4 years use, for which reason the initial cost for such a pump often is a barrier to this type of therapy. Although more complex than traditional syringes and pens, the pump offer the advantages of continuous infusion of insulin, precision in dosing and optionally programmable delivery profiles and user actuated bolus infusions in connections with meals.
Addressing the above problem, several attempts have been made to provide a second class of drug infusion devices that are low in cost and convenient to use. Some of these devices are intended to be partially or entirely disposable and may provide many of the advantages associated with an infusion pump without the attendant cost and inconveniencies, e.g. the pump may be prefilled thus avoiding the need for filling or refilling a drug reservoir. Examples of this type of infusion devices are known from U.S. Pat. Nos. 4,340,048 and 4,552,561 (based on osmotic pumps), U.S. Pat. No. 5,858,001 (based on a piston pump), U.S. Pat. No. 6,280,148 (based on a membrane pump), U.S. Pat. No. 5,957,895 (based on a flow restrictor pump (also know as a bleeding hole pump)), U.S. Pat. No. 5,527,288 (based on a gas generating pump), or U.S. Pat. No. 5,814,020 (based on a swellable gel) which all in the last decades have been proposed for use in inexpensive, primarily disposable drug infusion devices, the cited documents being incorporated by reference. U.S. Pat. No. 6,364,865 discloses a manually held infusion device allowing two vial-type containers to be connected and a pressure to be build up in one of the containers to thereby expel a drug contained in that container.
The disposable pumps generally comprises a skin-contacting mounting surface adapted for application to the skin of a subject by adhesive means, and with the infusion needle arranged such that in a situation of use it projects from the mounting surface to thereby penetrate the skin of the subject, whereby the place where the needle penetrates the skin is covered while the appliance is in use. The infusion needle may be arranged to permanently project from the mounting surface such that the needle is inserted simultaneously with the application of the infusion pump, this as disclosed in U.S. Pat. Nos. 2,605,765, 4,340,048 and in EP 1 177 802, or the needle may be supplied with the device in a retracted state, i.e. with the distal pointed end of the needle “hidden” inside the pump device, this allowing the user to place the pump device on the skin without the possibility of observing the needle, this as disclosed in U.S. Pat. Nos. 5,858,001 and 5,814,020. In addition to pumps, alternative means for transporting a fluid drug may be used, e.g. iontophoresis as discussed below.
Although it can be expected that the above described second class of fully or partly disposable infusion devices can be manufactured considerably cheaper than the traditional durable infusion pump, they are still believed to be too expensive to be used as a real alternative to traditional infusion pumps for use on an every-day basis.
Before turning to the disclosure of the present invention, a different type of device relying on the insertion of a needle or needle-like structure will be described.
Although the above-described drug infusion pumps, either disposable or durable, may provide convenience of use and improved treatment control, it has long been an object to provide a drug infusion system for the treatment of e.g. diabetes which would rely on closed loop control, i.e. being more or less fully automatic, such a system being based on the measurement of a value indicative of the condition treated, e.g. the blood glucose level in case of insulin treatment of diabetes. In principle, such systems have been known for more than two decades, see for example U.S. Pat. No. 4,245,634 which discloses an artificial beta cell for regulating blood glucose concentration in a subject by continuously analyzing blood from the patient and deriving a computer output signal to drive a pump which infuses insulin at a rate corresponding to the signal, however, mainly due to problems associated with the glucose sensors such systems have until today not been very successful. Although a closed loop system would be a desirable implementation of a given sensor system, such a sensor could also be utilized as a monitor system providing the patient with information for manually controlling treatment, e.g. insulin treatment by injections and/or infusion by pump.
A given monitor system for measuring the concentration of a given substance may be based on invasive or non-invasive measuring principles. An example of the latter would be a non-invasive glucose monitor arranged on the skin surface of a patient and using near-IR spectroscopy, however, the present invention is concerned with the introduction of a transcutaneous device such as a sensor element.
In recent years, a variety of electrochemical sensors have been developed for a range of applications, including medical applications for detecting and/or quantifying specific agents in a patient's blood. As one example, glucose sensors have been developed for use in obtaining an indication of blood glucose levels in a diabetic patient. As described above, such readings can be especially useful in monitoring and/or adjusting a treatment regimen which typically includes regular administration of insulin to the patient.
When a sensor element is introduced subcutaneously, the body responds to the element as an insult and produces a specialized biochemical and cellular response which may lead to the development of a foreign body capsule around the implant and consequently may reduce the flux of glucose to the sensor. Consequently, the percutaneous approach aims to acquire data during the first period of this tissue response.
The monitoring method can be of three types: non-reactive, reversibly reactive or irreversibly reactive. The type of sensor which, thus far, has been found to function most effectively in vivo is the amperometric sensor relying on irreversible, transport-dependent reactive glucose assays. For a detailed review of the different types of glucose sensors reference is made to Adam Heller, Implanted electrochemical glucose sensors for the management of diabetes, Annu. Rev. Biomed. Eng. 1999, 01:153-175.
The sensor may be placed subcutaneously being connected to external equipment by wiring or the substance (fluid) to be analysed may be transported to an external sensor element, both arrangements requiring the placement of a subcutaneous component, the present invention addressing both arrangements. However, for simplicity the term “sensor” is used in the following for both types of sensor elements.
Turning to the sensor elements per se, relatively small and flexible electrochemical sensors have been developed for subcutaneous placement of sensor electrodes in direct contact with patient blood or other extra-cellular fluid (see for example U.S. Pat. No. 5,482,473 incorporated by reference), wherein such sensors can be used to obtain periodic or continuous readings over a period of time. In one form, flexible transcutaneous sensors are constructed in accordance with thin film mask techniques wherein an elongated sensor includes thin film conductive elements encased between flexible insulative layers of polyimide sheet or similar material. Such thin film sensors typically include exposed electrodes at a distal end for transcutaneous placement in direct contact with patient blood or other fluid, and exposed conductive contacts at an externally located proximal end for convenient electrical connection with a suitable monitor device.
Insertion devices for this type of sensors are described in, among others, U.S. Pat. Nos. 5,390,671, 5,391,950, 5,568,806 and 5,954,643 which are hereby incorporated by reference.
DISCLOSURE OF THE INVENTIONHaving regard to the above-identified problems, it is an object of the present invention to provide a skin mountable medical device or system and components therefore, which allow such a device or system to be used in a convenient and cost-effective manner. The configuration of the system and the components therefore should contribute in providing a medical drug delivery or sensor assembly which allow for easy and swift operation yet being reliable in use.
In the disclosure of the present invention, embodiments and aspects will be described which will address one or more of the above objects or which will address objects apparent from the below disclosure as well as from the description of exemplary embodiments.
Thus, corresponding to a first aspect, a medical device is provided comprising a transcutaneous device unit and a process unit. The transcutaneous device unit comprises a first housing, a lower surface adapted for application to a skin surface of a subject, and a transcutaneous device. The process unit comprises a second housing comprising a lower surface adapted to face towards the skin surface of the subject, and a process assembly. The first and second housings are adapted to be coupled to each other such that at least a portion of the lower surface of the second housing is free to move relative to the skin surface when the first unit is attached to the skin surface and the first and second housings are coupled to each other. The coupling may be substantially rigid. The transcutaneous device unit may comprise a flexible patch portion having an upper surface and a lower surface with an adhesive, wherein at least a portion of the patch faces the lower surface of the second housing and is free to move relative thereto when the units are coupled to each other.
In a second aspect, a medical device is provided comprising a transcutaneous device unit and a process unit. The transcutaneous device unit comprises a flexible patch portion comprising an upper surface and a lower surface, the lower surface being adapted for application to a skin surface of a subject, a first housing, and a transcutaneous device. The process unit comprises a second housing comprising a lower surface, and a process assembly. The first and second housings are adapted to be coupled to each other with the lower surface of the second housing facing towards at least a portion of the upper surface of the patch portion, such that at least a portion of the flexible patch portion facing towards the lower surface of the second housing is free to move relative thereto. The coupling may be substantially rigid.
In a further aspect, a medical device is provided comprising a transcutaneous device unit and a process unit. The transcutaneous device unit comprises a flexible patch portion with an upper surface and a lower mounting surface adapted for application to a skin surface of a subject, a first housing, and a transcutaneous device arranged in the housing. The process unit comprises a second housing with a lower surface and a process assembly. The first and second housings are adapted to be secured to each other in such a way that at least a portion of the flexible patch portion facing the lower surface of the second housing is allowed to bend freely relative to the housing. The coupling may be substantially rigid.
In this way the relatively flexible patch portion can adapt to the skin surface to which it is mounted both statically and dynamically without being restricted in its movements by the normally much stiffer process unit. For example, if the flexible patch is arranged on a curved body portion it will be able to conform to the curvature both initially and during movement. Further, as the process unit is moved relative to the flexible patch the space between the two units is vented, this preventing build-up of moisture or heat. For example, most materials used for forming skin attachable patches are permeable to moisture, however, when a process unit is arranged directly onto the patch this capability is restricted unless the space between the two units are properly ventilated. To reduce the risk that the process unit is “caught” and thus pulled off the skin as it is lifted away from the patch portion it may be desirable to provide the patch portion with a degree of rigidity, e.g. by incorporation of stiffening structures, allowing only the flexibility necessary to provide the desired level of comfort and functionality. Alternatively, the lower surface of the process unit may fully or partly face directly against the skin, i.e. with no patch portion interposed, this allowing the space between the process unit and the skin to be vented as the process unit during use will be allowed to move relative to the skin.
In an exemplary embodiment a medical device is provided comprising a transcutaneous device unit and a process unit. The transcutaneous device unit comprises a flexible patch portion with upper and lower surfaces the lower surface being adapted for application to a skin surface of a subject, a first housing comprising a first coupling, and a transcutaneous device arranged in the housing. The process unit comprises a second housing with a lower surface and a second coupling arranged at a peripheral portion of the second housing, and a process assembly. The first and second couplings are adapted to be connected to each other with the upper surface of the patch facing towards the lower surface of the second housing, such that the flexible patch portion facing towards the lower surface of the second housing is substantially free to move relative thereto. For most applications, the two couplings will provide a substantially rigid connection between the two housings.
To enhance venting between the process unit and the patch the lower surface of the second housing and the upper surface of the patch may be formed to prevent full engagement between the two surfaces when they are arranged against each other. For example, at least one of the two units may be provided with a raised portion providing a free space between the two units when they are arranged against each other. To further enhance venting the patch portion facing towards the second housing may comprise one or more cut-out portions whereby a portion of the lower surface of the second housing in a situation of use faces the skin surface of the subject to which the medical device is arranged.
In an exemplary embodiment the transcutaneous device unit comprises a flexible sheet member with an upper and a lower surface, the lower surface being provided with a medical grade adhesive allowing the transcutaneous device unit to be attached to a skin surface of a subject, wherein the first housing comprises a lower surface attached to the upper surface of the flexible sheet member, e.g. by adhesive or by welding. The sheet may be from a woven or non-woven material or from a laminate thereof and preferably possesses good breathability providing a high degree of wearer comfort. One or more layers, e.g. the layer providing the upper surface, may be weldable allowing for attachment of the first housing by welding.
To support the first housing and improve its attachment to the sheet material one or more support members may be provided extending from the first housing, the support member being attached to the upper surface of the sheet member. In this way such a support member may serve also as a raised element as disclosed above.
In an exemplary embodiment the transcutaneous device unit comprises a transcutaneous drug delivery device, and the process unit comprises a reservoir adapted to contain a fluid drug, and an expelling assembly adapted for cooperation with the reservoir to expel fluid drug out of the reservoir and through the skin of the subject via the transcutaneous drug delivery device when the two units are coupled to each other.
The transcutaneous drug delivery device (which term also covers the similar terms transcutaneous access device and transcutaneous access tool traditionally used in this technical field) may be in the form of e.g. a pointed hollow infusion needle, a micro needle array, or a combination of a relatively flexible per se blunt cannula with a pointed insertion needle may provide a pointed transcutaneous device, the insertion needle being retractable after insertion of the blunt portion of the transcutaneous device. In the latter case the portion of the transcutaneous device actually placed in the subject does not necessarily comprise a pointed end allowing the combined transcutaneous device to be inserted through the skin, such a pointed end being withdrawn during insertion of the transcutaneous device. The cannula is advantageously soft and flexible relative to the insertion needle which typically is a solid steel needle. In the disclosure of the present invention as well as in the description of the exemplary embodiments, reference will mostly be made to a transcutaneous device in the form of an infusion needle. The length of the transcutaneous device may be chosen in accordance with the actual application, e.g. a hollow steel needle which may be inserted at a substantially right angle relative to the skin surface may have an inserted length of 2-8 mm, preferably 3-5 mm, whereas a cannula which may also be inserted at an oblique angle relative to the skin surface may be somewhat longer, e.g. 4-20 mm. Indeed, the first housing may comprise more than one transcutaneous drug delivery device.
The transcutaneous device unit may be supplied with e.g. a needle, soft cannula or sensor projecting from the mounting surface, however, to limit the risk of accidental needle injuries, the pointed end of the transcutaneous device is advantageously moveable between an initial position in which the skin-penetrating end is retracted relative to the mounting surface, and an extended position in which the pointed end projects relative to the mounting surface. Depending on the intended method of mounting the device on the user, the transcutaneous device may be moved between the two positions as the two units are connected to each, as would be appropriate in case the transcutaneous device unit is mounted on the skin of the user before the reservoir unit is connected. However, in case the two units are intended to be connected to each other before assembled units are mounted on the skin of the user, the transcutaneous device unit advantageously comprises user-actuatable actuation means for moving the pointed end of the transcutaneous device between the initial and the extended position.
To further reduce the likelihood of transcutaneous device injuries, the skin-penetrating end of the transcutaneous device may be moveable between the extended position in which the skin-penetrating end projects relative to the mounting surface, and a retracted position in which the skin-penetrating end is retracted relative to the mounting surface. Correspondingly, the combined device may comprise user-actuatable retraction means for moving the skin-penetrating end of the transcutaneous device between the extended and the retracted position when the retraction means is actuated. To prevent re-use of the transcutaneous device, the transcutaneous device may be permanently locked in its retraced position.
The transcutaneous drug delivery device may also be in the form of a transcutaneous device comprising no skin penetrating elements, e.g. a jet injection device or electrodes allowing an ionic agent to permeate from a predetermined site on the surface of skin into the subcutaneous tissue of the subject by using the principle of iontophoresis. For a more thorough discussion of iontophoresis reference is made to U.S. Pat. No. 6,622,037 hereby incorporated by reference.
The term expelling assembly covers an aggregation of components or structures which in combination provides that a fluid can be expelled from the reservoir. The expelling assembly may e.g. be a mechanical pump (e.g. a membrane pump, a piston pump or a roller pump) in combination with electronically controlled actuation means, a mechanically driven pump (e.g. driven by a spring), a gas driven pump or a pump driven by an osmotic engine. The expelling assembly may also me in the form of an aggregation of components or structures which in combination provides that a fluid can be expelled from the reservoir when the expelling assembly is controlled or actuated by a controller external to the expelling assembly. Depending on the nature of the transcutaneous device the expelling assembly may be of different configuration and nature. For example, when one or more hollow infusion needles or cannulas are used, the expelling assembly may be arranged to force or suck the fluid drug from the reservoir, whereas in the case of iontophoresis the expelling means would be means for applying a current over a set of electrodes, i.e. “driving” means.
In a further exemplary embodiment the transcutaneous device unit comprises a transcutaneous sensor device and the process unit is adapted to transmit and/or process data acquired via the sensor. As with the transcutaneous drug delivery device, a sensor device may be non-penetrating or penetrating. A non-penetrating sensor may allow a body parameter to be sensed in the subcutaneous space, e.g. by using a light source and light detector, or by transporting fluid from the subcutaneous space to the skin surface, e.g. by applying a current across the skin surface. A penetrating sensor may allow a body parameter to be sensed in the subcutaneous space, e.g. by using a needle formed sensor as discussed in the introduction, or by transporting fluid from the subcutaneous space to detection assembly by means of a conduit, this principle being known as micro-dialysis. An example of a penetrating needle-sensor and a corresponding process unit is shown in U.S. Pat. No. 6,809,653 (hereby incorporated by reference) which discloses a characteristic monitor system including a data receiving device, a transcutaneous needle sensor for producing signal indicative of a characteristic of a subject (e.g. a blood glucose value), and a processor device. The processor device includes a housing, a sensor connector, a processor, and in the shown embodiment a transmitter. In the shown embodiment the processor coupled to the sensor processes the signals from the sensor for transmission to the remotely located data receiving device, however, the processed data could also be shown directly on a display provided on the processor device. The data receiving device may be a characteristic monitor, a data receiver that provides data to another device, a wireless programmer for a medical device (e.g. a remote control), a medication delivery device (such as an infusion pump), or the like.
As used herein, the term “drug” is meant to encompass any drug-containing flowable medicine capable of being passed through a delivery means such as a hollow needle in a controlled manner, such as a liquid, solution, gel or fine suspension. Representative drugs include pharmaceuticals such as peptides, proteins, and hormones, biologically derived or active agents, hormonal and gene based agents, nutritional formulas and other substances in both solid (dispensed) or liquid form. In the description of the exemplary embodiments reference will be made to the use of insulin. Correspondingly, the term “subcutaneous” infusion is meant to encompass any method of transcutaneous delivery to a subject. Further, the term needle (when not otherwise specified) defines a piercing member adapted to penetrate the skin of a subject.
In the following the invention will be further described with references to the drawings, wherein
In the figures like structures are mainly identified by like reference numerals.
DESCRIPTION OF EXEMPLARY EMBODIMENTSWhen in the following terms such as “upper” and “lower”, “right” and “left”, “horizontal” and “vertical” or similar relative expressions are used, these only refer to the appended figures and not to an actual situation of use. The shown figures are schematic representations for which reason the configuration of the different structures as well as there relative dimensions are intended to serve illustrative purposes only.
Firstly, with reference to
More specifically,
The needle unit comprises a flexible patch portion 10 with a lower adhesive mounting surface adapted for application to the skin of a user, and a housing portion 20 in which a hollow infusion needle (not shown) is arranged. The needle comprises a skin-penetrating distal end, e.g. pointed, adapted to penetrate the skin of a user, and is adapted to be arranged in fluid communication with the reservoir unit. In the shown embodiment the pointed end of the needle is moveable between an initial position in which the pointed end is retracted relative to the mounting surface, and an extended position in which the pointed end projects relative to the mounting surface. Further, the needle is moveable between the extended position in which the pointed end projects relative to the mounting surface, and a retracted position in which the pointed end is retracted relative to the mounting surface. The needle unit further comprises user-gripable actuation means in the form of a first strip-member 21 for moving the pointed end of the needle between the initial and the second position when the actuation means is actuated, and user-gripable retraction in the form of a second strip-member 22 means for moving the pointed end of the needle between the extended and the retracted position when the retraction means is actuated. As can be seen, the second strip is initially covered by the first strip. The housing further comprises user-actuatable male coupling means 31 in the form of a pair of resiliently arranged hook members adapted to cooperate with corresponding female coupling means on the reservoir unit, this allowing the reservoir unit to be releasable secured to the needle unit in the situation of use. The flexible patch portion comprises a flexible sheet 12 and a flexible support plate 11 extending from the housing, the support plate further comprising a flexible ridge formed support member 13 extending from the housing. The support plate as well as the housing may be fully or partly attached to the flexible sheet, e.g. by welding or adhesives. In case the housing and/or plate are only partly attached (i.e. corresponding to one or more areas located between the sheet and the housing and/or plate) the sheet will be able to partially move relative to the housing and/or plate. In use a peripheral portion of the sheet extends from the assembled device as the reservoir unit covers only the support plate of the upper surface of the patch. The adhesive surface is supplied to the user with a peelable protective sheet.
The reservoir unit 5 comprises a pre-filled reservoir containing a liquid drug formulation (e.g. insulin) and an expelling assembly for expelling the drug from the reservoir through the needle in a situation of use. The reservoir unit has a generally flat lower surface adapted to be mounted onto the upper surface of the patch portion, and comprises a protruding portion 50 adapted to be received in a corresponding cavity of the housing portion 20 as well as female coupling means 51 adapted to engage the corresponding hook members 31 on the needle unit. The protruding portion provides the interface between the two units and comprises a pump outlet and contact means (not shown) allowing the pump to be started as the two units are assembled. The lower surface also comprises a window (not to be seen) allowing the user to visually control the contents of the reservoir before the two units are connected.
First step in the mounting procedure is to assemble the two units by simply sliding the reservoir unit into engagement with the needle unit (
After the device has been left in place for the recommended period of time for use of the needle unit (e.g. 48 hours)—or in case the reservoir runs empty or for other reasons—it is removed from the skin by gripping and pulling the retraction strip 22 which leads to retraction of the needle followed by automatic stop of drug infusion where after the strip which is attached to the adhesive patch is used to remove the device from the skin surface.
When the device has been removed the two units are disengaged by simultaneously depressing the two hook members 31 allowing the reservoir unit 5 to be pulled out of engagement with the needle unit 2 which can then be discarded. Thereafter the reservoir unit can be used again with fresh needle units until it has been emptied.
In the shown embodiment the patch portion has the same general shape as the combined device albeit somewhat larger. In alternative embodiments the patch may comprise openings or cut-out portions. For example, an area between the two support legs may be cut out allowing the underlying skin to better breath. In the shown embodiments the couplings are arranged on “vertical” portions of the housings, however, coupling components may also be arranged on “horizontal” portions of the housings.
As seen is the user gripable portion 551 of the release member initially covered by a portion of the actuation member, this reducing the probability that the user erroneously uses the release member instead of the actuation member. Further, the actuation and release members (or portion thereof) may be colour coded to further assist the user to correctly use the device.
For example, the actuation member may be green to indicate “start” whereas the release member may be red to indicate “stop”.
To actuate the needle the user grips the flexible strip forming the user gripable portion 541 (which preferably comprises adhesive portions to hold it in its shown folded initial position) and pulls the needle actuation portion 542 out of the housing, the actuation member 540 thereby fully disengaging the housing. More specifically, when the ramp surface 544 is moved it forces the latch 527 away from the lower arm to thereby release it, after which the release portion 528 disengages the ramp allowing the two legs to be pulled out of the housing. As seen in
In the shown embodiment the release member is in the form of a strip formed from a flexible material and having an inner and an outer end, the strip being threaded through an opening 512 in the housing, the strip thereby forming the user gripable portion 551 and the needle retraction portion 552, the inner end of the strip being attached to the housing and the outer end of the strip being attached to a peripheral portion of the sheet member 570 or, alternatively, a peripheral portion of the housing. In the projection shown in
When the user decides to remove the needle unit from the skin, the user grips the user gripable portion 551, lifts it away from the housing and pulls it upwardly whereby the loop shortens thereby forcing the lower arm upwardly, this position corresponding to an intermediate release state. By this action the lower arm engages the inclined edge portion 529 of the catch 527 thereby forcing it outwardly until it snaps back under the lower arm corresponding to the position shown in
Advantageously, the actuation and release members may be formed and arranged to communicate with the reservoir unit (not shown). For example, one of the legs of the actuation member may in its initial position protrude through the housing to thereby engage a corresponding contact on the reservoir unit, this indicating to the reservoir unit that the needle unit has been attached, whereas removal of the actuation member will indicate that the needle has been inserted and thus that drug infusion can be started. Correspondingly, actuation of the release member can be used to stop the pump.
In
The control and actuation means comprises a pump actuating member in the form of a coil actuator 581 arranged to actuate a piston of the membrane pump, a PCB or flex-print to which are connected a microprocessor 583 for controlling, among other, the pump actuation, contacts 588, 589 cooperating with the contact actuators on the needle unit, signal generating means 585 for generating an audible and/or tactile signal, a display (not shown) and an energy source 586. The contacts are preferably protected by membranes which may be formed by flexible portions of the housing.
In
In the above described embodiments, the transcutaneous device has been in the form of a unitary needle device (e.g. an infusion needle as shown or a needle sensor (not shown)), however, the transcutaneous device may also be in the form of a cannula or a sensor in combination with an insertion needle which is withdrawn after insertion thereof. For example, the first needle portion may be in the form of a (relatively soft) infusion cannula (e.g. a Teflon® cannula) and a there through arranged removable insertion needle. This type of cannula needle arrangement is well known from so-called infusion sets, such infusion sets typically being used to provide an infusion site in combination with (durable) infusion pumps.
Thus,
In a situation of use the assembly is moved downwardly, either manually or by a releasable insertion aid, e.g. a spring loaded member acting through an opening in the housing (not shown) whereby the cannula with the projecting insertion needle is inserted through the skin of a subject. In this position the lower member engages the coupling member 657 to thereby lock the cannula in its extended position, just as the coupling member 667 is released by the release member 622 thereby allowing the upper member to return to its initial position by means of the first spring.
When the user intends to remove the delivery device from the skin surface, the user grips the gripping portion of the tab and pulls it in a first direction substantially in parallel with the skin surface, by which action the flexible strip 677 releases the coupling member 657 from the lower member whereby the lower member and thereby the cannula is retracted by means of the second spring. When the cannula has been withdrawn from the skin, the user uses the now unfolded tab to pull off the entire delivery device from the skin surface, for example by pulling the tab in a direction away from the skin surface.
In the above description of the preferred embodiments, the different structures and means providing the described functionality for the different components have been described to a degree to which the concept of the present invention will be apparent to the skilled reader. The detailed construction and specification for the different components are considered the object of a normal design procedure performed by the skilled person along the lines set out in the present specification.
In the following a number of concepts for the introduction of a cannula, e.g. a soft cannula or catheter, will be described. Advantageously, the different concepts may be used in combination with a ventilated skin mountable device as described above.
Claims
1. A medical device (500), comprising a transcutaneous device unit and a process unit, the transcutaneous device unit (502) comprising:
- a first housing (503),
- a lower surface adapted for application to a skin surface of a subject, and
- a transcutaneous device (530, 651), the process unit comprising:
- a second housing (501) comprising a lower surface adapted to face towards the skin surface of the subject, and
- a process assembly (300, 580, 760), wherein the first and second housings are adapted to be coupled to each other, and wherein at least a portion of the lower surface of the second housing is free to move relative to the skin surface when the first unit is attached to the skin surface and the first and second housings are coupled to each other.
2. A medical device as in claim 1, wherein the transcutaneous device unit comprises a flexible patch portion (570) comprising an upper surface and a lower surface, the lower surface being adapted for application to the skin surface of the subject, and wherein the first and second housing are adapted to be coupled to each other with the lower surface of the second housing facing towards at least a portion of the upper surface of the patch portion, and wherein at least a portion of the flexible patch portion facing towards the lower surface of the second housing is free to move relative thereto.
3. A medical device as in claim 1, wherein the transcutaneous device unit comprises a flexible patch portion comprising an upper surface and a lower surface, the lower surface being adapted for application to the skin surface of the subject, the first housing comprising a first coupling (511), wherein the process unit comprises a second coupling (506) arranged at a peripheral portion of the second housing, and wherein the first and second couplings can be connected to each other with the upper surface of the patch portion facing towards the lower surface of the second housing, and wherein the flexible patch portion facing towards the free lower surface of the second housing is free to move relative thereto.
4. A medical device as in claim 2, wherein the lower surface of the second housing and the upper surface of the patch is formed to prevent full engagement between the two surfaces when they are arranged against each other.
5. A medical device as in claim 4, wherein at least one of the two units comprises a raised portion (561) providing a free space between the two units when they are arranged against each other.
6. A medical device as in claim 2, wherein the patch portion facing towards the second housing comprises a cut-out portion
7. A medical device as in claim 1, wherein the transcutaneous device unit comprises a flexible sheet member with an upper and a lower surface, the lower surface comprising an adhesive allowing the transcutaneous device unit to be attached to the skin surface of the subject, the first housing comprising a lower surface attached to the upper surface of the flexible sheet member.
8. A medical device as in claim 6, wherein a support (11, 561) extends from the first housing, the support being attached to the upper surface of the sheet member.
9. A medical device as in claim 1, wherein the coupling is substantially rigid
10. A medical device as in claim 1, wherein the transcutaneous device unit comprises a transcutaneous drug delivery device (530, 651), and the process unit comprises a reservoir (760) adapted to contain a fluid drug, and an expelling assembly (300) adapted for cooperation with the reservoir to expel fluid drug out of the reservoir and through the skin of the subject via the transcutaneous drug delivery device when the two units are coupled to each other.
11. A medical device as in claim 1, wherein the transcutaneous device unit comprises a transcutaneous sensor device and the process unit is adapted to transmit and/or process data acquired via the sensor.
12. A medical device as in claim 1, wherein the transcutaneous device in an initial state is arranged in a retracted position at least partially within the first housing, the transcutaneous device being adapted to be moved from the retracted position to an extended position, this allowing the transcutaneous device to be inserted into the subject when the transcutaneous device unit has been arranged on the skin surface of the subject.
Type: Application
Filed: Dec 2, 2005
Publication Date: Feb 19, 2009
Applicant: Novo Nordisk A/S (Denmark)
Inventors: Erik Winkel Ethelfeld (Copenhagen), Nicolai Michael Schmidt (Naerum), John Stern Nielsen (Allerod)
Application Number: 11/792,355
International Classification: A61M 5/32 (20060101);